From abc9af02de6ca2dec7f4c4256e0523a207c85ce3 Mon Sep 17 00:00:00 2001
From: Nathan Fisher <jeang3nie@hitchhiker-linux.org>
Date: Wed, 23 Aug 2023 15:57:53 -0400
Subject: [PATCH] Implement random in-crate, remove all dependencies

---
 .gitignore  |  1 +
 Cargo.lock  | 68 -----------------------------------------------------
 Cargo.toml  |  1 -
 src/main.rs | 20 ++++++++--------
 4 files changed, 11 insertions(+), 79 deletions(-)

diff --git a/.gitignore b/.gitignore
index ea8c4bf..fd9f291 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /target
+*.core
diff --git a/Cargo.lock b/Cargo.lock
index 6c1309f..ced3267 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,74 +2,6 @@
 # It is not intended for manual editing.
 version = 3
 
-[[package]]
-name = "cfg-if"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
-
-[[package]]
-name = "getrandom"
-version = "0.2.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c05aeb6a22b8f62540c194aac980f2115af067bfe15a0734d7277a768d396b31"
-dependencies = [
- "cfg-if",
- "libc",
- "wasi",
-]
-
-[[package]]
-name = "libc"
-version = "0.2.140"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99227334921fae1a979cf0bfdfcc6b3e5ce376ef57e16fb6fb3ea2ed6095f80c"
-
 [[package]]
 name = "liff"
 version = "1.0.0"
-dependencies = [
- "rand",
-]
-
-[[package]]
-name = "ppv-lite86"
-version = "0.2.17"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b40af805b3121feab8a3c29f04d8ad262fa8e0561883e7653e024ae4479e6de"
-
-[[package]]
-name = "rand"
-version = "0.8.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
-dependencies = [
- "libc",
- "rand_chacha",
- "rand_core",
-]
-
-[[package]]
-name = "rand_chacha"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
-dependencies = [
- "ppv-lite86",
- "rand_core",
-]
-
-[[package]]
-name = "rand_core"
-version = "0.6.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
-dependencies = [
- "getrandom",
-]
-
-[[package]]
-name = "wasi"
-version = "0.11.0+wasi-snapshot-preview1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
diff --git a/Cargo.toml b/Cargo.toml
index 0855b4d..7b8dd3e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,7 +10,6 @@ path = "src/main.rs"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-rand = "0.8"
 
 [profile.release]
 codegen-units = 1
diff --git a/src/main.rs b/src/main.rs
index 992ba31..8d0461e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,11 +1,8 @@
-use {
-    rand::Rng,
-    std::{
-        env,
-        fs::{self, DirEntry},
-        io::{self, Write},
-        path::PathBuf,
-    },
+use std::{
+    env,
+    fs::{self, DirEntry, File},
+    io::{self, Read, Write},
+    path::PathBuf,
 };
 
 fn get_datadirs() -> Vec<PathBuf> {
@@ -57,8 +54,11 @@ fn get_files() -> Vec<PathBuf> {
 fn main() -> Result<(), io::Error> {
     let files = get_files();
     let len = files.len();
-    let mut rng = rand::thread_rng();
-    let idx = rng.gen_range(0..len);
+    let mut buf = [0; 4];
+    let mut fd = File::open("/dev/urandom")?;
+    fd.read_exact(&mut buf)?;
+    let idx = u32::from_ne_bytes(buf);
+    let idx: usize = usize::try_from(idx).unwrap() % len;
     if let Some(path) = files.get(idx) {
         let contents = fs::read(path)?;
         io::stdout().write_all(&contents)?;